Pendrin, the protein encoded by the Pendred syndrome gene (PDS), is an apical porter of iodide in the thyroid and is regulated by thyroglobulin in FRTL-5 cells.
نویسندگان
چکیده
Pendred syndrome is an autosomal recessive disorder characterized by congenital deafness and thyroid goiter. The thyroid disease typically develops around puberty and is associated with a mild organification defect, characterized by an inappropriate discharge of iodide upon perchlorate stimulation (a positive perchlorate discharge test). The gene (PDS) mutated in Pendred syndrome is expressed in thyroid and encodes a 780-amino acid protein (pendrin) that has recently been shown to function as an iodide/chloride transporter. We sought to establish the location of pendrin in the thyroid and to examine the regulatory network controlling its synthesis. Using peptide-specific antibodies for immunolocalization studies, pendrin was detected in a limited subset of cells within the thyroid follicles, exclusively at the apical membrane of the follicular epithelium. Interestingly, significantly greater amounts of pendrin were encountered in thyroid tissue from patients with Graves' disease. Using a cultured rat thyroid cell line (FRTL-5), PDS expression was found to be significantly induced by low concentrations of thyroglobulin (TG), but not by TSH, sodium iodide, or insulin. This is different from the established effect of TG, more typically a potent suppressor of thyroid-specific gene expression. Together, these results suggest that pendrin is an apical porter of iodide in the thyroid and that the expression and function of both the apical and basal iodide porters are coordinately regulated by follicular TG.
منابع مشابه
Functional differences of the PDS gene product are associated with phenotypic variation in patients with Pendred syndrome and non-syndromic hearing loss (DFNB4).
The PDS gene encodes a transmembrane protein, known as pendrin, which functions as a transporter of iodide and chloride. Mutations in this gene are responsible for Pendred syndrome and autosomal recessive non-syndromic hearing loss at the DFNB4 locus on chromosome 7q31. A screen of 20 individuals from the midwestern USA with non-syndromic hearing loss and dilated vestibular aqueducts identified...
متن کاملExpression of pendrin and the Pendred syndrome (PDS) gene in human thyroid tissues.
The gene recently cloned that is responsible for the Pendred syndrome (PDS), an autosomal recessive disease characterized by goiter and congenital sensorineural deafness, is mainly expressed in the thyroid gland. Its product, designated pendrin, was shown to transport chloride and iodide. To investigate whether the PDS gene is altered during thyroid tumorigenesis, PDS gene expression and pendri...
متن کاملMinireview: The sodium-iodide symporter NIS and pendrin in iodide homeostasis of the thyroid.
Thyroid hormones are essential for normal development and metabolism. Thyroid hormone biosynthesis requires iodide uptake into the thyrocytes and efflux into the follicular lumen, where it is organified on selected tyrosyls of thyroglobulin. Uptake of iodide into the thyrocytes is mediated by an intrinsic membrane glycoprotein, the sodium-iodide symporter (NIS), which actively cotransports two ...
متن کاملA coherent organization of differentiation proteins is required to maintain an appropriate thyroid function in the Pendred thyroid.
CONTEXT Pendred syndrome is caused by mutations in the gene coding for pendrin, an apical Cl-/I- exchanger. OBJECTIVE To analyze intrathyroidal compensatory mechanisms when pendrin is lacking, we investigated the thyroid of a patient with Pendred syndrome. The expression of proteins involved in thyroid hormone synthesis, markers of oxidative stress (OS), cell proliferation, apoptosis, and ant...
متن کاملAnoctamin-1/TMEM16A is the major apical iodide channel of the thyrocyte.
Iodide is captured by thyrocytes through the Na(+)/I(-) symporter (NIS) before being released into the follicular lumen, where it is oxidized and incorporated into thyroglobulin for the production of thyroid hormones. Several reports point to pendrin as a candidate protein for iodide export from thyroid cells into the follicular lumen. Here, we show that a recently discovered Ca(2+)-activated a...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Endocrinology
دوره 141 2 شماره
صفحات -
تاریخ انتشار 2000